[1.0.X] Fixed #9882 -- Added `alters_data = True` to `BaseModelForm.save` method, thanks dc.

Backport of r9678 from trunk.


git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@9679 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/forms/models.py

@@ -318,6 +318,8 @@ class BaseModelForm(BaseForm):
             fail_message = 'changed'
         return save_instance(self, self.instance, self._meta.fields, fail_message, commit)
 
+    save.alters_data = True
+
 class ModelForm(BaseModelForm):
     __metaclass__ = ModelFormMetaclass